All About Hemophilia Replacement Therapy
Hemophilia replacement therapy is the main form of treatment for moderate to severe hemophilia. During treatment, missing clotting factors, which are either made from donated human blood or produced synthetically (also called DNA derived), are slowly injected or dripped into a vein, often through a port which has been surgically implanted in the chest.
Depending on the specific kind of hemophilia diagnosis, any missing or low clotting factors such as factor VIII (hemophilia A), or IX (hemophilia B) are added. These kinds of treatments provide a short-term clotting solution as the factor can drop by half in as little as 12 hours for factor VIII. Factor IX, which is used for hemophilia B, tends to last longer (18-24 hours).
Because of this, treatments often need to be repeated frequently. Newer forms of longer lasting clotting factor replacements are being developed which can potentially extend the time between infusions from days to weeks. In 2015, two longer lasting forms were approved by the FDA.
How do You Measure How Severe Hemophilia A is?
Mild hemophilia A: can cause excessive bleeding after a traumatic injury or surgical procedure. This includes individuals with 6% to 49% of factor VIII in their blood. Roughly 6-30% of all cases are considered mild.
Moderate hemophilia A: can cause spontaneous bleeding episodes with unknown causes, as well as bleeding episodes after an injury. This includes those who have 1% to 5% of factor VIII in their blood. Approximately 15% of all cases are considered moderate.
Severe hemophilia A: can cause excessive bleeding following even minor trauma, with frequent episodes of spontaneous bleeds, which can include bleeding into muscles and joints. This group includes people who have less than 1% of factor VIII in their blood. About 25% of cases are considered severe.
Prophylactic Hemophilia Replacement Therapy
Hemophilia replacement therapy may be used to help stop a bleed in progress, or prophylactically (as a preventative measure), to avert or lessen the severity of bleeding events before they can occur, such as when there is an upcoming dental visit or scheduled surgery.
Blood Borne Illnesses: Are Clotting Factors Derived from Blood Products Safe?
Blood clotting factors that are derived from donated blood products are carefully screened, heat-treated, and or washed with solvents to remove any potential contamination such as HIV, hepatitis, or other blood borne illnesses. Due to these precautions, the risk of receiving tainted blood products is considered very low.
Synthetic Factors
The risk of contaminated blood products can be eliminated altogether by basing care on synthetic clotting factors. These are created using cloned genes from specific clotting factors. Roughly 75% of people with hemophilia use recombinant, or synthetic, factor VIII.
How long does it take to administer clotting factors?
It takes about 15-20 minutes to administer a clotting factor. Synthetic clotting factor concentrates, known as recombinant clotting factors, can be safely stored at home and prepared for use on an as needed basis.
On-demand therapy is less expensive and involved than preventative clotting replacement therapy. Home administration of clotting replacement therapy allows for:
• Fewer visits to the emergency room or doctor’s office
• Reduced costs of treatment (as opposed to on site medical settings)
• Faster treatment for bleeding episodes
• More involvement of the individual (which may help children learn to take greater responsibility for their ongoing care)
The benefits of Prevention Versus on Demand Clotting Replacement Therapy
A Joint Outcome Study published in 2009 noted that regular prophylaxis (preventative treatment), especially when started prior to the age of two (and followed thereafter), reduced the amount of joint damage caused by bleeding episodes.
The study was carried out over a four decades and included forty boys with an average age of four at the start of the study.
Participants in the study were divided into two groups: the first group was given prophylactic hemophilia replacement therapy, and the other group was given on-demand replacement therapy. Over time, boys in the on-demand group had more bleeds and displayed more joint damage than those who were treated prophylactically.
Complications of Hemophilia Replacement Therapy
People with moderate to severe hemophilia, especially those with the rarer form of hemophilia B, may develop what is known as inhibitor complications. The human immune system is tasked with identifying and neutralizing substances, such as bacteria and viruses that the body does not recognize.
To do this, it creates specialized proteins known as antibodies. These antibodies can inhibit, or interfere, with replacement clotting factors, hence the term “inhibitor”.
If the clotting factor does not seem to be working as expected, tests may be required to determine if the person receiving replacement therapy has developed an inhibitor. An inhibitor can be classified as high or low responding, depending on how many inhibitors are present.
According to the National Heart, Lung and Blood Institute, roughly 20-30% of people with severe hemophilia A will develop some degree of inhibitor. If an inhibitor does develop, healthcare providers may increase the amount of clotting factor administered or try other clotting factor sources. In some cases, inhibitors may require what are known as bypassing agents.
These special blood products bypass, or work around, inhibitors to help the body form clots, even in the presence of inhibitors. In some cases, the inhibitors may also clear up on their own.
Other Types of Hemophilia Medications and Treatment
Hemophilia replacement therapy is not the only treatment for the disorder. Supportive medications can also be used to help prevent bleeding episodes. Click here to learn more about managing hemophilia.
ASP Cares Supports Those Affected by Hemophilia
ASP Cares is a leading resource for people living with bleeding disorder such as hemophilia. Whether you, or your child, needs hemophilia replacement therapy, or other related information, we can help.
As experts in all areas of hemophilia, we provide ongoing support, information, medications delivered right to your door, and help with alternative funding to pay for the cost of necessary medications. Click here for more information.
**Disclaimer**
This content does not represent medical advice. It is not meant to diagnose or treat any condition. It is not intended as a substitute for the advice of a qualified medical provider.
